Rotational symmetry of classical orbits, arbitrary quantization of angular momentum and the role of the gauge field in two-dimensional space

We study quantum classical correspondence in terms of the coherent wave functions of a charged particle in two-dimensional central-scalar potentials as well as the gauge field of a magnetic flux in the sense that the probability clouds of wave functions are well localized on classical orbits. For both closed and open classical orbits, the non-integer angular-momentum quantization with the level space of angular momentum being greater or less than h is determined uniquely by the same rotational symmetry of classical orbits and probability clouds of coherent wave functions, which is not necessarily 27r-periodic. The gauge potential of a magnetic flux impenetrable to the particle cannot change the quantization rule but is able to shift the spectrum of canonical angular momentum by a flux-dependent value, which results in a common topological phase for all wave functions in the given model. The well-known quantum mechanical anyon model becomes a special case of the arbitrary quantization, where the classical orbits are 2π-periodic.

Two-fold symmetry of the in-plane resistance in kagome superconductor Cs(V_(1-x)Ta_x)_3Sb_5 with enhanced superconductivity

The kagome superconductor CsV_3Sb_5 has attracted widespread attention due to its rich correlated electron states including superconductivity, charge density wave(CDW), nematicity, and pair density wave. Notably, the modulation of the intertwined electronic orders by the chemical doping is significant to illuminate the cooperation/competition between multiple phases in kagome superconductors. In this study, we have synthesized a series of tantalum-substituted Cs(V_(1-x)Ta_x)_3Sb_5 by a modified self-flux method. Electrical transport measurements reveal that CDW is suppressed gradually and becomes undetectable as the doping content of x is over 0.07. Concurrently, the superconductivity is enhanced monotonically from T_c ~ 2.8 K at x = 0 to 5.2 K at x = 0.12. Intriguingly, in the absence of CDW, Cs(V_(1-x)Ta_x)_3Sb_5(x = 0.12) crystals exhibit a pronounced two-fold symmetry of the in-plane angular-dependent magnetoresistance(AMR) in the superconducting state, indicating the anisotropic superconducting properties in the Cs(V_(1-x)Ta_x)_3Sb_5. Our findings demonstrate that Cs(V_(1-x)Ta_x)_3Sb_5 with the non-trivial band topology is an excellent platform to explore the superconductivity mechanism and intertwined electronic orders in quantum materials.

A NEW METHOD FOR NUMERICAL SIMULATION OF TWO TRAINS PASSING BY EACH OTHER AT THE SAME SPEED

A new method is proposed to numerically simulate problems of trains passing by each other at the same speed, and is implemented in UDF language of commercial software Fluent. Because only a half of the computational domain is required and the dynamic mesh technique is avoided, the computational efficiency is greatly improved. A two-dimensional test case is used for validation, which shows that the flow field and the pressure wave during the train-passing events can be correctly calculated by this new method. This method can be easily extended to three-dimensional simulations, to deal with practical problems.

Classification of gradient steady Ricci solitons with linear curvature decay

In this paper,we study steady Ricci solitons with a linear decay of sectional curvature.In particular,we give a complete classification of 3-dimensional steady Ricci solitons and 4-dimensional K-noncollapsed steady Ricci solitons with non-negative sectional curvature under the linear curvature decay.

Spherical Logistic Distribution

Some of the spherical distributions can be constructed through proper transformation of the densities on plane.Since the logistic density on the Euclidean space has similar behavior to the normal distribution,it is of interest to extend it for spherical data.In this paper,we introduce spherical logistic distribution on the unit sphere and then study relevant statistical inferences including parameters estimation through method of moments and maximum likelihood techniques.It is shown that the spherical logistic distribution is a multimodal distribution with the marginal logistic density function.Proposed density has rotational symmetry property and this plays a key role to drive some important results related to first two moments.To investigate the proposed density in more details,some simulation studies along with analyzing real-life data are also considered.

Qualitative tool for designing natural protected areas and ecological restoration projects

The rotational symmetry connection between the Species-Area Relationship(SAR)and Endemics-Area Relationship(EAR)was discovered in the frame of Species-Area Theory.In this paper,this paired connection was applied into the impact of variation of number of species and area and dynamic change of species-abundance distribution on the curve shape of SAR and EAR,which can be integrated into the assessment of Natural Protected Areas and Ecological Restoration Projects.The results indicate that the underestimate or overestimate of total number of species can lead to the underestimate or overestimate of extinction rate,while the reduction or expansion of area can lead to the increase or decrease in extinction rate.In addition,the species-abundance distribution change of community causes the shape tuning of SAR and EAR,which leads to inconsistent change of extinction rate.Thus,this SAT frame can be used as a qualitative tool in conservation and restoration management.